Caribbean bats, less than in prehistory

Some 25,000 years ago, bats once dominated the Caribbean. Did rising sea levels drive them away?

Tue Nov 13, 2012 11:26 AM ET

About 25,000 years ago, the Earth was a very different planet. It was deep in the midst of a geological period referred to as the “last glacial maximum,” meaning the last time when the planet was so cold that glaciers reached down from the North Pole into North America, Europe and Asia.

Some of the islands were many times larger than they are at present, and they teemed with many species of bats. The fossil evidence for these bats surrounds the islands, and scientists have long wondered what [killed] them off.

One theory was human hunting, and another was that the caves these bats loved were inundated with water as sea level rose.

Writing in a new paper published this week in Ecology and Evolution, biologists Liliana M. Dávalos and Amy L. Russell argue that the evidence overwhelmingly points to rising sea levels as the culprit. As the glaciers melted, sea levels rose so rapidly that the island bats couldn’t find a new home quickly enough — and so they died out.

Dávalos and Russell note that this die-off gives us a snapshot of what might happen to wildlife on Earth over the next few centuries as water levels rise rapidly.

While we may not be certain how many inches the ocean will rise as the polar regions melt, we can be sure of one thing. Historical evidence demonstrates that sea level rises lead to extinctions.